Wireless mobile communication technology uses various standards and protocols to transmit data between a transmission station and a wireless mobile device. Some wireless devices communicate using orthogonal frequency-division multiplexing (OFDM) combined with a desired digital modulation scheme via a physical layer. Standards and protocols that use OFDM include the third generation partnership project (3GPP) long term evolution (LTE), the Institute of Electrical and Electronics Engineers (IEEE) 802.16 standard (e.g., 802.16e, 802.16m), which is commonly known to industry groups as WiMAX (Worldwide interoperability for Microwave Access), and the IEEE 802.11 standard, which is commonly known to industry groups as WiFi.
In 3GPP radio access network (RAN) LTE systems, the transmission station can be a combination of Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node Bs (also commonly denoted as evolved Node Bs, enhanced Node Bs, eNodeBs, or eNBs) and Radio Network Controllers (RNCs), which communicates with the wireless mobile device, known as a user equipment (UE). A downlink (DL) transmission can be a communication from the transmission station (or eNodeB) to the wireless mobile device (or UE), and an uplink (UL) transmission can be a communication from the wireless mobile device to the transmission station.
In homogeneous networks, the transmission station, also called macro nodes, can provide basic wireless coverage to mobile devices in a cell. Heterogeneous networks (HetNets) are used to handle the increased traffic loads on the macro nodes due to increased usage and functionality of mobile devices. HetNets can include a layer of planned high power macro nodes (or macro-eNBs) overlaid with layers of lower power nodes (micro-eNBs, pico-eNBs, femto-eNBs, or home eNBs [HeNBs]) that can be deployed in a less well planned or even entirely uncoordinated manner within the coverage area of the macro nodes. The macro nodes can be used for basic coverage, and the low power nodes can be used to fill coverage holes, to improve capacity in hot-zones or at the boundaries between the macro nodes' coverage areas, and improve indoor coverage where building structures impede signal transmission. Inter-cell interference coordination (ICIC) or enhanced ICIC (eICIC) may be used for resource coordination to reduce interference between the transmission stations (or nodes), such as macro nodes and low power nodes. In ICIC an interfering node (or an aggressor node) may give up use of some resources in order to enable control and data transmissions between a victim node or victim mobile device.
The transmission stations, such as the macro nodes and/or lower power nodes (LPN), can also be grouped together with other transmission stations in a Coordinated MultiPoint (CoMP) system where transmission stations from multiple cells can transmit signals to the mobile device and receive signals from the mobile device.
Reference will now be made to the exemplary embodiments illustrated, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended.